How to Find a Developer to Fix Your App (and What to Send Them First)

Short answer: Look for a developer who has taken over other people's code before and works in your app's tech stack (React Native, Swift, Kotlin, Flutter and so on). Before the first call, gather access to the code repository, the developer accounts and the crash reports, plus a written list of the problems with steps to reproduce. Expect a short, paid audit first, then a fix plan with estimates. Good developers stabilise the app before adding features, and rarely recommend a full rewrite as a first step.

"My app is broken and my developer is gone" is one of the most stressful spots to be in as an app owner. Here's how to get out of it efficiently.

What kind of developer do I need?

Not every great developer is great at fixing someone else's app. Look for:

Experience in your stack. Find out what the app is built with first (see below).
Takeover experience. Ask: "Tell me about an app you inherited. What was wrong, and what did you do first?"
Live apps they maintain. Check their apps' version history in the App Store. Regular updates show they keep things running.
Calm, methodical communication. Rescue work is about diagnosis before action.

How do I find out what my app is built with?

If you don't know, check:

The code repository: package.json with react-native or expo means React Native, pubspec.yaml means Flutter, .xcodeproj with Swift files means native iOS, Gradle with Kotlin files means native Android
Old invoices or contracts from the previous developer
Ask any developer to look. It takes them two minutes with repository access

What should I send a developer first?

The more of this you have, the faster and cheaper the fix:

Access: code repository, Apple Developer and Google Play Console (add them as a team member, never share your password), backend (Firebase, AWS and so on), and crash reporting
A problem list: each issue with steps to reproduce, device and OS version, and screenshots or screen recordings
Priority: what's costing you money or users right now?
History: when it started breaking, and what changed around then (an OS update, a new release, a developer leaving)
Business context: how many users, whether there's revenue, and any deadlines

If you don't have access to the code or accounts, start with securing your accounts. Nothing else can happen without them.

What does a fix engagement look like?

1. Audit (fixed scope, usually days): get the app building, review crash reports, check purchases and accounts, scan dependencies and security, and reproduce the reported bugs.

2. Written findings: what's broken, why, the risk if it's left alone, and an estimate for each fix.

3. Stabilise: fix revenue-impacting bugs and top crashes first, then store compliance, then the build pipeline. (Fixing crashes)

4. Ship carefully: staged rollouts so a new release reaches a small percentage of users first.

5. Ongoing: move to a maintenance plan, or back to feature work once things are stable. (App maintenance)

What are the most common reasons apps "suddenly break"?

A new iOS or Android version changed behaviour or deprecated an API
Store requirements: Google Play's yearly target API level deadline, or Apple's minimum SDK requirement for new uploads. Your app might still work but you can't ship updates. (Updating an outdated app)
Expired certificates, keys or tokens for push notifications or third-party APIs
A third-party service changed or shut down its API
Backend costs or limits were hit (an unpaid bill, quota exceeded)
A rushed release with untested changes

Should I fix or rewrite?

Usually fix. Rewrites take longer than anyone estimates and freeze your progress in the meantime. Rewrite only if the app is on an abandoned technology, the core data model can't support the product, or fixing would genuinely cost more. A good developer will show you that maths rather than just recommending a rewrite.

How do I avoid paying twice?

Keep ownership of all accounts and code from now on
Get written estimates per fix, and agree how overruns are handled
Ask for brief documentation: how to build, release and configure the app
Prefer developers who explain what they changed in plain English

FAQ

How much does it cost to fix an app?

It depends entirely on what's wrong. A short audit is usually a small fixed fee, and the fix plan gives you per-item estimates. Simple fixes can take hours, while deep structural problems take weeks.

Can a new developer fix an app someone else built?

Yes, as long as you have the source code and account access. Apps built on mainstream frameworks are much easier for another developer to pick up.

What if I don't have the source code?

Check your contract for ownership terms and ask the previous developer to transfer it. If it truly can't be recovered, the app has to be rebuilt, though your designs, data and store listing can usually be kept.

Do you fix apps you didn't build?

Yes. I take over and maintain React Native, Expo and web apps built by other developers and agencies. Get in touch with a short description of what's wrong.